Not Applicable
Not Applicable
A source code appendix, Appendix A, is included. This appendix resides on two duplicate CD-R discs. The discs are entitled xe2x80x9cCallaway Appendix A,xe2x80x9d and each disc contains two ascii-format source code files for the Zilog Z8 microcontroller: xe2x80x9cSOURCE.TXT,xe2x80x9d and xe2x80x9cINCLUDE.INC.xe2x80x9d
This invention is an apparatus that allows a musical conductor to practice conducting a piece of music with no orchestra present.
Modem and classical music can be transcribed into MIDI (Musical Instrument Digital Interface) computer files as xe2x80x98digitalxe2x80x99 music. Unlike CDs or MP3s, MIDI files do not contain any actual sound data. MIDI files consist only of a list of note events, which are made into sounds by a synthesizer. For example, the opening phrase xe2x80x98Happy birthday to youxe2x80x9d would contain 6 discrete note events.
MIDI files contain multiple instruments, where an instrument consists of a specific list of note events. A string quartet MIDI file has four instruments, and therefore four distinct lists of note events. A solo piano MIDI file has only one instrument.
Synchronizationxe2x80x94Controlling MIDI Tempo with an External Signai
A software MIDI player can play back music much like a CD player. A xe2x80x98playxe2x80x99 button in MIDI player software starts the music, and a xe2x80x98stopxe2x80x99 button ends it. During the playback, the note events for each instrument are sent separately to a synthesizer.
Popular software MIDI players allow flexible control of musical tempo for applications more complex than simple playback. One application that requires special tempo control is synchronization. Synchronization is necessary when a MIDI player must be locked in simultaneous playback with another machine. For example, a MIDI player can be synchronized to a video recorder. When the video recorder begins playback, it sends a control signal to the MIDI player. The control signal from the video recorder controls the speed (or tempo) of the MIDI player""s playback. When the video recorder stops, the MIDI player stops. When the video player changes speeds, the control signal causes the MIDI player to change speeds as well. The control signal is made up of individual timing markers, or xe2x80x98MIDI Beat Clocks.xe2x80x99 MIDI Beat Clocks are subdivisions of musical beats. Every musical beat is subdivided into twenty-four MIDI Beat Clocks. This means that the video recorder, or other controlling machine, must send exactly twenty-four MIDI Beat Clocks for the MIDI Player to advance its music by one beat.
Using Synchronization to Allow Real-Time Human Conducting
A human conductor can control the tempo of a MIDI file with a device that generates synchronization data. A conducting device allows a user to establish tempo in real time, with the music following in synchronization. The conducting device translates this activity into MIDI Beat Clocks, which are sent to a MIDI player. The MIDI player derives its tempo from the incoming MIDI Beat Clocks as if it were synchronized to a video recorder. When the user speeds up the tempo, the MIDI Time Code also speeds up, and the MIDI player plays back the music more quickly.
Devices that Generate MIDI Beat Clocks
Over the last 20 years, conducting devices have been popular projects in the academic world. However, very few conducting devices have been brought to market. No conducting device that has been introduced has been widely embraced by musicians. However, other electronic instruments flourish in the marketplace. Digital pianos, wind instruments, and motion-detecting sound modules such as the Theremin are in wide use among modern musicians.
The Radio Baton
A system for tracking musical gestures, disclosed in 1990 in U.S. Pat. No. 4,980,519 by Matthews, incorporated batons that contained radio transmitters. As the batons moved about in three-dimensional space, their motion was detected by an xe2x80x98antenna boardxe2x80x99 lying beneath them. The antenna board received signals sent from the two batons using multiple radio receivers. By comparing the relative strength of the received signals, a computer could calculate XYZ position coordinates for the two batons. This position data was sent as a control signal to a computer running musical software. The control signal could be configured to govern a variety of musical signals, including tempo. The complexity of this system caused it to be expensive.
Lightning II
The xe2x80x98Lightning IIxe2x80x99 MIDI controller was a baton-based system for tracking motion and gestures. It operated by deriving XYZ position coordinates from strobing LEDs. Two handheld batons each contained LEDs that strobed at unique fixed frequencies. An external array of optical sensors used triangulation to calculate XYZ position coordinates for the two batons. This system was expensive and fragile, and the batons were so heavy as to be objectionable to musical conductors. (see http:/www.buchla.com/lightning/descript.html)
The Digital Baton
A hand-held conducting device, disclosed in 1999 in U.S. Pat. No. 5,875,257 by Marrin, used internal accelerometers and strobing LEDs to detect conducting gestures. The device provided multiple control signals for the conducting of music, including tempo and volume. This system used a heavy baton, so that it could not accommodate extended conducting sessions.
The Conductor""s Jacket
A custom-fitted jacket, developed by Nakra, contains biometric sensors. The jacket measures body motion and muscle action, and a computer combines these measurements to create a control signal. The control signal is used to govern a variety of musical parameters in live performance, including tempo, volume, and dynamics. This system is expensive and requires heavy calibration for each user. (see http:/web.media.mit.edu/xcx9cmarrin/CIM.htm)
Roland Dimension Beam
A system that detected the position of a hand in an operational space was disclosed in 1998 in U.S. Pat. No. 5,998,727 by Takahashi et al. The system used optical sensors to collect light reflected from the hand, and estimated the position of the hand through a process of triangulation. The system allowed a user to define specific MIDI parameters, and to control them with the signal generated through the optical triangulation. Both the sources of light and the optical detectors were contained in a single enclosure. Because of the crude method of triangulation used to detect the position of the hand, this system allowed only rough control of analog parameters, and not precise triggering of events. Triggering was particularly infeasible if a baton, instead of a hand, was used.
Every system that has been designed for conducting to date has suffered from some combination of the following disadvantages:
Heavy or bulky interfaces
Elements that must be worn on the body
Poor tracking of beats (i.e. beats are missed or skipped)
High cost ($1,200-$20,000)
Complex hardware installations
A user""s most common objection to a conducting device is typically its weight. Conducting a symphony or opera can be a 4-hour endeavor, and conductors often favor super lightweight batons in performance. Some conductors decline to use batons, even though this makes them less visible to musicians. The handheld component of most conducting devices weigh over 10 ounces, while a conductor""s baton weighs 1-5 ounces.
Objects and Advantages
In contrast to past efforts, the present device distinguishes itself by:
a. Allowing the user to hold any baton, or no baton;
b. Enabling simple manufacture and calibration, with few complex assembly steps or parameters requiring calibration;
c. Manufacturability at a cost typical of digital instruments (e.g. keyboards)
d. Providing lower sensitivity to false triggers.
e. Providing high beat resolution. Whether the musical gestures are made rapidly or very slowly, triggering is consistent.
The present invention comprises a device for detecting the gestures of a musical conductor. The system uses a laser beam projected into an optical sensor. When a conductor""s baton breaks the laser beam, the device sends a control signal to a computer.